| 摘要 |
<p>PURPOSE:To provide the title pigment which is red and gives printing ink or paints having excellent clarity, tinting power, gloss and resistance to water and heat, consisting of a novel gamma type crystal form having an X-ray diffraction pattern totally different from that of alpha type crystal. CONSTITUTION:A diazo component obtd. by diazotizing an amine of formula I at not higher than 5 deg.C is coupled with a coupler component obtd. by dissolving an acid of formula II in an aq. NaOH soln., at not higher than 5 deg.C to obtain a monoazo dye of formula III. The dye is suspended in, e.g., an aq. soln. of sodium resinate. The suspension is heated at 46-70 deg.C and an aq. soln. of a Ba salt is added thereto. The mixture is reacted at not higher than 70 deg.C to form a lake, thus obtaining the title pigment having a gamma type crystal form, represented by formula IV and characterized by an X-ray diffraction pattern with high diffraction intensity at an angle of diffraction (2<theta>+ or -0.2 deg.; Cu-Kalpha) of 5.0 deg., medium diffraction intensity at angles of diffraction of 14.8 deg., 24.7 deg. and 25.3 deg. and relatively low diffraction intensity at angles of diffraction of 9.8 deg., 11.1 deg., 18.3 deg., 19.3 deg., 26.6 deg. and 27.4 deg..</p> |
